Tair (Redis® OSS-Compatible):Test network connectivity between an ECS instance and a Tair instance

Procedure

1. Obtain the instance endpoint. For more information, see View endpoints.

2. Log on to the ECS instance that hosts your client and run the ping command.

   For example, if the instance endpoint is r-bp1zx****.redis.rds.aliyuncs.com, run the following command:

   ping r-bp1zx****.redis.rds.aliyuncs.com

   Note

   You can run this command on both Windows and Linux operating systems.

3. Review the test results.

   • On Windows, the command returns test results after four pings. The following example shows a sample output.

     Note

     To continuously test connectivity, run the ping <host> -t command.

     Figure 1. Ping command on a Windows server

     C:\Users\Administrator>ping xxx.redis.rds.aliyuncs.com
     Pinging xxx.redis.rds.aliyuncs.com [xxx.xxx.xxx.4] with 32 bytes of data:
     Reply from xxx.xxx.xxx.4: bytes=32 time<1ms TTL=128
     Reply from xxx.xxx.xxx.4: bytes=32 time<1ms TTL=128
     Reply from xxx.xxx.xxx.4: bytes=32 time<1ms TTL=128
     Reply from xxx.xxx.xxx.4: bytes=32 time<1ms TTL=128
     Ping statistics for xxx.xxx.xxx.4:
         Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
     Approximate round-trip times in milliseconds:
         Minimum = 0ms, Maximum = 0ms, Average = 0ms

   • On Linux, the command continuously sends ping requests. Press Ctrl+C to stop the command and view the statistics. The following example shows a sample output.

     Figure 2. Ping command on a Linux server

     [root@yaozhou ~]# ping xxx.redis.rds.aliyuncs.com
     PING xxx.redis.rds.aliyuncs.com (xxx) 56(84) bytes of data.
     64 bytes from xxx (xxx): icmp_seq=1 ttl=64 time=0.625 ms
     64 bytes from xxx (xxx): icmp_seq=2 ttl=64 time=0.644 ms
     64 bytes from xxx (xxx): icmp_seq=3 ttl=64 time=0.634 ms
     64 bytes from xxx (xxx): icmp_seq=4 ttl=64 time=0.640 ms
     64 bytes from xxx (xxx): icmp_seq=5 ttl=64 time=0.634 ms
     64 bytes from xxx (xxx): icmp_seq=6 ttl=64 time=0.635 ms
     64 bytes from xxx (xxx): icmp_seq=7 ttl=64 time=0.643 ms
     64 bytes from xxx (xxx): icmp_seq=8 ttl=64 time=0.638 ms
     64 bytes from xxx (xxx): icmp_seq=9 ttl=64 time=0.635 ms
     64 bytes from xxx (xxx): icmp_seq=10 ttl=64 time=0.631 ms
     ^C
     --- xxx.redis.rds.aliyuncs.com ping statistics ---
     10 packets transmitted, 10 received, 0% packet loss, time 9001ms
     rtt min/avg/max/mdev = 0.625/0.635/0.644/0.034 ms

Result analysis

• If all requests receive a reply, as shown in the preceding examples, the connection is normal.

• If requests fail or time out, there is a connection issue. Common causes include:

  • Domain name resolution fails. For more information, see Resolve connection issues caused by DNS failure.

  • A "Destination Host Unreachable" error occurs. For more information, see Solutions for "Destination Host Unreachable" errors.

  • Abnormal behavior of an ECS instance triggered a security policy, blocking the service. Check the server and configure precise outbound rules in the security group to allow the ECS instance to access only required addresses and ports, such as port 6379 of the instance. For more information, see Security group rules.

  • A firewall on the ECS instance or an intermediate network device might be blocking the connection. Check the firewall settings on the ECS instance and any relevant network infrastructure.